U.S. patent number 5,973,093 [Application Number 08/757,206] was granted by the patent office on 1999-10-26 for polymerizable polyol (allyl carbonate) composition.
This patent grant is currently assigned to PPG Industries Ohio, Inc.. Invention is credited to John C. Crano, Randy E. Daughenbaugh, Robert D. Herold, Charles R. Wiedrich.
United States Patent |
5,973,093 |
Daughenbaugh , et
al. |
October 26, 1999 |
**Please see images for:
( Certificate of Correction ) ** |
Polymerizable polyol (allyl carbonate) composition
Abstract
Describes polymerizable organic compositions of a major amount
of a first monomer component which is a polyol(allyl carbonate),
e.g., diethylene glycol bis(allyl carbonate), and from about 2 to
35 weight percent of a second monomer component which is an
alkoxylated bisphenol (or hydrogenated bisphenol) having acrylate
or methacrylate groups, e.g., dimethacrylate of bisphenol A having
25 to 35 ethoxy units. Substantially completely cured polymerizates
prepared from such compositions may be used to prepare photochromic
articles, e.g., lenses, by incorporating a photochromic substance,
e.g., by thermal transfer, into the polymerizate.
Inventors: |
Daughenbaugh; Randy E. (Turtle
Creek, PA), Herold; Robert D. (Monroeville, PA),
Wiedrich; Charles R. (Murrysville, PA), Crano; John C.
(Murrysville, PA) |
Assignee: |
PPG Industries Ohio, Inc.
(Cleveland, OH)
|
Family
ID: |
25046841 |
Appl.
No.: |
08/757,206 |
Filed: |
November 27, 1996 |
Current U.S.
Class: |
526/314; 252/586;
252/589; 526/319; 526/328.5; 526/333; 526/323.2; 430/962;
526/323.1; 430/495.1; 526/260 |
Current CPC
Class: |
G02B
1/041 (20130101); G03C 1/733 (20130101); C08F
290/062 (20130101); G02B 1/041 (20130101); C08L
31/00 (20130101); Y10S 430/163 (20130101); C08F
222/1025 (20200201) |
Current International
Class: |
G03C
1/73 (20060101); C08F 222/10 (20060101); C08F
222/00 (20060101); C08F 290/00 (20060101); C08F
290/06 (20060101); G02B 1/04 (20060101); C08F
220/00 (20060101); C08F 220/28 (20060101); C08F
018/24 (); C08L 035/02 (); G03C 001/73 () |
Field of
Search: |
;526/314-323.2,323.1,333,260,319 ;252/586,589 ;430/495.1,962 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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62-195383 |
|
Aug 1987 |
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JP |
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WO 96/18926 |
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Jun 1996 |
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WO |
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WO 96/19741 |
|
Jun 1996 |
|
WO |
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WO96/340245 |
|
Oct 1996 |
|
WO |
|
Other References
Techniques of Chemistry, Photochromism, vol. 3, "Photochromic
Processes Involving Heterolytic Cleavage", R. C. Bertelson, Chap.
3, pp. 48-55, pp. 252-254, pp 399, p 842,
Wylie-Interscience..
|
Primary Examiner: Zitomer; Fred
Attorney, Agent or Firm: Stein; Irwin M. Franks; James
R.
Claims
We claim:
1. A polymerizable organic composition comprising:
(a) a major amount of a first monomer component represented by the
following general formula,
wherein R is a radical derived from a polyol, R.sub.1 is a radical
derived from an allyl or substituted allyl group and i is a whole
number from 2 to 6; and
(b) from 2% to 35% by weight, based on the total weight of monomer
components, of a second monomer component represented by the
following general formula, ##STR16## wherein m and n are each a
positive number, the sum of m and n being from 5 to 70, R.sub.3 and
R.sub.4 are each hydrogen or methyl, R.sub.5 and R.sub.6 are each
hydrogen or C.sub.1 to C.sub.2 alkyl, and A is a divalent linking
group selected from the group consisting of straight or branched
chain alkylene, phenylene, C.sub.1 -C.sub.9 alkyl substituted
phenylene, and a group represented by the following general
formula, ##STR17## wherein, R.sub.7 and R.sub.8 are each C.sub.1
-C.sub.4 alkyl, chlorine or bromine, p and q are each an integer
from 0 to 4, ##STR18## represents a divalent benzene group or a
divalent cyclohexane group and X is O, s, --S(O.sub.2)--, --C(O)--,
--CH.sub.2 --, --CH.dbd.CH--, --C(CH.sub.3).sub.2 --,
--C(CH.sub.3)(C.sub.6 H.sub.5)-- or ##STR19## when ##STR20## is the
divalent benzene group, and X is O, S, --CH.sub.2 --, or
--C(CH.sub.3).sub.2 -- when ##STR21## is the divalent cyclohexane
group.
2. The polymerizable organic composition of claim 1 wherein the
polyol from which R is derived is a poly(c.sub.2 -C.sub.4)alkylene
glycol or 4,4'-isopropylidenediphenol, i is 2, the sum of m and n
is from 10 to 40, and A is a divalent linking group represented by
the following general formula, ##STR22## wherein ##STR23##
represents a divalent benzene group.
3. The polymerizable organic composition of claim 2 wherein the
polyol from which R is derived is diethylene glycol, R.sub.1 is the
allyl group, the sum of m and n is from 25 to 35, R.sub.3 and
R.sub.4 are each methyl, R.sub.5 and R.sub.6 are each hydrogen, p
and q are each 0, and X is --C(CH.sub.3).sub.2 --.
4. The polymerizable organic composition of claim 3 wherein the
second monomer component is present in an amount of from 2% to 15%
by weight.
5. The polymerizable organic composition of claim 1 further
comprising from 0.5% to 30% by weight, based on the total weight of
monomer components, of a third monomer component having ethylenic
unsaturation and being polymerizable by free radical initiation,
said third monomer component being different from said first and
second monomer components.
6. The polymerizable organic composition of claim 5 wherein the
third monomer component is selected from the group consisting of
methyl methacrylate, vinyl acetate, triallyl cyanurate,
pentaerythritol tetraacrylate, and mixtures thereof.
7. The polymerizable organic composition of claim 5 wherein the
third monomer component is an aliphatic polyurethane monomer having
terminal unsaturated groups selected from acrylyl, methacrylyl and
allyl groups, and mixtures of such unsaturated groups.
8. The polymerizable organic composition of claim 1 further
comprising a nonpolymerizable flexibilizing additive in an amount
of from 0.05% to 15% by weight, based on the total weight of
monomer components and said nonpolymerizable flexibilizing
additive.
9. The polymerizable organic composition of claim 8 wherein said
nonpolymerizable flexibilizing additive is selected from the group
consisting of poly(alkylene glycol) dibenzoate, esters of phthalic
acid, esters of isophthalic acid, esters of terephthalic acid and a
member represented by the following general formula, ##STR24##
wherein e and f are each a positive number, the sum of e and f
being from 0 to 70, R.sub.5 and R.sub.6 are each hydrogen or
C.sub.1 to C.sub.2 alkyl, and A is a divalent linking group
selected from the group consisting of straight or branched chain
alkylene, phenylene, C.sub.1 -C.sub.9 alkyl substituted phenylene
and a group represented by the following general formula, ##STR25##
wherein, R.sub.7 and R.sub.8 are each C.sub.1 -C.sub.4 alkyl,
chlorine or bromine, p and q are each an integer from 0 to 4,
##STR26## represents a divalent benzene group or a divalent
cyclohexane group and X is O, S, --S(O.sub.2)--, --C(O)--,
--CH.sub.2 --, --C(CH.sub.3).sub.2 --, --C(CH.sub.3)(C.sub.6
H.sub.5)-- or ##STR27## when ##STR28## is the divalent benzene
group, and X is O, S, --CH.sub.2 --, or --C(CH.sub.3).sub.2 -- when
##STR29## is the divalent cyclohexane group.
10. The polymerizable organic composition of claim 5 further
comprising a nonpolymerizable flexibilizing additive in an amount
of from 0.05% to 15% by weight, based on the total weight of
monomer components and said nonpolymerizable flexibilizing
additive.
11. The polymerizable organic composition of claim 10 wherein said
nonpolymerizable flexibilizing additive is selected from the group
consisting of poly(alkylene glycol) dibenzoate, esters of phthalic
acid, esters of isophthalic acid, esters of terephthalic acid and a
group represented by the following general formula, ##STR30##
wherein e and f are each a positive number, the sum of e and f
being from 0 to 70, R.sub.5 and R.sub.6 are each hydrogen or
C.sub.1 to C.sub.2 alkyl, and A is a divalent linking group
selected from the group consisting of straight or branched chain
alkylene, phenylene, C.sub.1 -C.sub.9 alkyl substituted phenylene
and a group represented by the following general formula, ##STR31##
wherein, R.sub.7 and R.sub.8 are each C.sub.1 -C.sub.4 alkyl,
chlorine or bromine, p and q are each an integer from 0 to 4,
##STR32## represents a divalent benzene group or a divalent
cyclohexane group and is O, S, --S(O.sub.2)--, --C(O)--, --CH.sub.2
--, --C(CH.sub.3).sub.2 --, --C(CH.sub.3)(C.sub.6 H.sub.5)-- or
##STR33## when ##STR34## is the divalent benzene group, and X is O,
S, --CH.sub.2 --, or --C(CH.sub.3).sub.2 -- when ##STR35## is the
divalent cyclohexane group.
12. The polymerizate of claim 1.
13. The polymerizate of claim 4.
14. The polymerizate of claim 5.
15. The polymerizate of claim 8.
16. The polymerizate of claim 10.
17. A photochromic article comprising:
(a) the polymerizate of claim 12; and
(b) a photochromic amount of organic photochromic substance.
18. A photochromic article comprising:
(a) the polymerizate of claim 13; and
(b) a photochromic amount of organic photochromic substance.
19. The photochromic article of claim 18 wherein the organic
photochromic substance is selected from the group consisting of
spiro(indoline)naphthoxazines, spiro(indoline)benzoxazines,
benzopyrans, naphthopyrans, chromenes, organo-metal dithizonates,
fulgides and fulgimides and mixtures of such organic photochromic
substances.
20. A photochromic article comprising:
(a) the polymerizate of claim 14; and
(b) a photochromic amount of organic photochromic substance.
21. A photochromic article comprising:
(a) the polymerizate of claim 15; and
(b) a photochromic amount of organic photochromic substance.
22. A photochromic article comprising:
(a) the polymerizate of claim 16; and
(b) a photochromic amount of organic photochromic substance.
Description
DESCRIPTION OF THE INVENTION
The present invention relates to polymerizable organic compositions
and polymerizates prepared therefrom, particularly polymerizates
having organic photochromic substances applied to or incorporated
therein. More particularly, the present invention relates to
certain polymerizable organic compositions that contain a major
amount of a polyol(allyl carbonate) first monomer component and a
second monomer component having acrylate or methacrylate groups.
Still more particularly, this invention relates to photochromic
articles prepared from polymerizates of such polymerizable organic
compositions. Photochromic articles prepared in accordance with the
present invention have been observed to exhibit an improved
photochromic response.
Polymerizable organic compositions based on polyol(allyl
carbonate), particularly diethylene glycol bis(allyl carbonate),
and polymerizates obtained therefrom are well known in the art.
Polymerizates of polymerizable organic compositions based on
homopolymers of diethylene glycol bis(allyl carbonate) possess
excellent clarity, good flexibility and abrasion resistance.
However, when cured substantially completely, it is difficult to
incorporate organic photochromic substances into such polymerizates
by diffusion.
Photochromism is a phenomenon involving a change in color of a
photochromic substance, or an article containing such a substance,
upon exposure to light radiation containing ultraviolet rays, such
as ultraviolet radiation contained in sunlight or in the light of a
mercury lamp, and a reversion to the original color when the
influence of the ultraviolet radiation is discontinued.
Discontinuation of the ultraviolet radiation can be achieved for
example by storing the photochromic substance or article in the
dark or by removing the source of ultraviolet radiation. Recently,
photochromic plastic materials, particularly plastic materials for
optical applications, have been the subject of considerable
attention. In particular, photochromic ophthalmic plastic lenses
have been investigated in part due to the weight advantage that
they can offer relative to ophthalmic lenses made of glass. In
addition, photochromic transparencies for vehicles, such as
automobiles and airplanes, have been of interest because of the
potential safety features that such transparencies offer.
Fully cured polymerizates based on homopolymers of polyol(allyl
carbonate), for example diethylene glycol bis(allyl carbonate), are
not particularly well suited to having organic photochromic
substances incorporated therein by diffusion. Consequently, a
homopolymer of polyol(allyl carbonate) is often initially
undercured prior to having the organic photochromic substance
incorporated therein by diffusion, followed by an additional curing
step to fully cure the polymer. Such a two-stage cure process
requires extra time and expense.
U.S. Pat. No. 5,556,931 discloses polymerizable compositions
comprising at least two ethoxylated bisphenol A dimethacrylate type
monomers. The composition is described as having 30 to 80 mole % of
a monomer having 2 to 3 ethoxy units, 20 to 50 mole % of a monomer
having 6 to 12 ethoxy units, and less than 20 mole % of a monomer
having other than 2 to 3 and 6 to 12 ethoxy units. U.S. Pat. No.
5,545,828 discloses organic ophthalmic lenses prepared from the
polymerization of a composition comprising at least 50% by weight
of an ethoxylated bisphenol A dimethacrylate type monomer having 0
to 10 ethoxy units. U.S. Pat. No. 5,442,022 discloses a
polymerizate obtained by the polymerization of a polymerisable
composition comprising, in part, at least 50% by weight of an
ethoxylated bisphenol A dimethacrylate type monomer, or mixture of
such monomers, having 0 to 10 ethoxy units.
International patent publication WO 96/19741 discloses organic
photochromic materials consisting of a polymer matrix of optical
quality and of at least one dye that imparts photochromic
properties to the matrix. The polymer constituting the matrix may
be a copolymer of 30 to 95 weight % ethoxylated bisphenol A
dimethacrylate having 2 to 4 ethoxy units, and 5 to 70 weight % of
a polyurethane oligomer having terminal di- or triacrylic or di- or
trimethacrylic functionality. International patent publication WO
96/18926 discloses photochromic transparent organic materials
particularly useful for the production of photochromic organic
ophthalmic lenses. The organic materials are chosen from
homopolymers of ethoxylated bisphenol A dimethacrylate having 2 to
4 ethoxy units, and copolymers of such dimethacrylates, and at most
30 weight % of an aromatic monomer with vinyl, acrylic or
methacrylic functionality. The above patents and patent
applications do not disclose ethoxylated bisphenol A dimethacrylate
type monomers in combination with polyol(allyl carbonate) type
monomers.
U.S. Pat. No. 4,306,780 discloses a high refractive index lens
obtained by copolymerization of an ethoxylated bisphenol A
dimethacrylate type monomer having 0 to 8 ethoxy units. Example 14
of U.S. Pat. No. 4,306,780 discloses the combination of bisphenol A
dimethacrylate (BPDMA) with phenylmethacrylate and
CR-39.sup..circle-w/dot. diethylene glycol bis(allyl carbonate)
monomer.
It has now been discovered that substantially completely cured
polymerizates prepared from polymerizable organic compositions of
the present invention show essentially no loss in physical
properties, such as flexibility and abrasion resistance, compared
to polymerizates obtained from homopolymers of diethylene glycol
bis(allyl carbonate). It has further been discovered that
photochromic articles prepared from polymerizates made in
accordance with the present invention have an improved photochromic
response compared to photochromic articles prepared from
homopolymers of diethylene glycol bis(allyl carbonate).
Polymerizable organic compositions according to the present
invention are comprised of a major amount of a first monomer
component, which is represented by the following general formula
I,
wherein R is a radical derived from a polyol, R.sub.1 is a radical
derived from a substituted or unsubstituted allyl group and i is a
whole number from 2 to 6, preferably 2 to 3, more preferably 2, and
from 2% to 35% by weight, based on the total weight of monomer
components, of a second monomer component, which is represented by
the following general formula II, ##STR1## wherein m and n are each
a positive number, the sum of m and n being from 5 to 70, R.sub.3
and R.sub.4 are each hydrogen or methyl, R.sub.5 and R.sub.6 are
each hydrogen or C.sub.1 to C.sub.2 alkyl, preferably hydrogen or
methyl and A is a divalent linking group selected from the group
consisting of straight or branched chain alkylene (usually
containing from 1 to 8 carbon atoms), phenylene, C.sub.1 -C.sub.9
alkyl substituted phenylene and a group represented by the
following general formula III, ##STR2## wherein R.sub.7 and R.sub.8
are each C.sub.1 -C.sub.4 alkyl, chlorine or bromine, p and q are
each an integer from 0 to 4, ##STR3## represents a divalent benzene
group or a divalent cyclohexane group, and X is O, S,
--S(O.sub.2)--, --C(O)--, --CH.sub.2 --, --CH.dbd.CH--,
--C(CH.sub.3).sub.2 --, --C(CH.sub.3)(C.sub.6 H.sub.5)-- or
##STR4## when ##STR5## is the divalent benzene group, and X is O,
S, --CH.sub.2 --, or --C(CH.sub.3).sub.2 -- when ##STR6## is the
divalent cyclohexane group.
Optionally from 0.5% to 30% by weight, based on the total weight of
monomer components, of a third monomer component, having ethylenic
unsaturation and being polymerizable by free radical initiation,
may also be present in the polymerizable organic compositions of
the present invention. The third monomer component is different
from the first and second monomer components.
As used herein with regard to e and f, and m and n, unless
otherwise stated, "number" is meant to mean "average number". Other
than in the operating examples, or where otherwise indicated, all
numbers expressing quantities of ingredients or reaction conditions
used herein are to be understood as modified in all instances by
the term "about".
DETAILED DESCRIPTION OF THE INVENTION
In accordance with the present invention, there are provided
certain polymerizable organic compositions comprising a major
amount of a first monomer component, as defined above with respect
to general formula I. The first monomer component may be described
as being a polyol(allyl carbonate). Polyol(allyl carbonate)
monomers that may be used in the aforedescribed polymerizable
organic composition are allyl carbonates of linear or branched
aliphatic or aromatic polyols, e.g., aliphatic glycol bis(allyl
carbonate) compounds and alkylidene bisphenol bis(allyl carbonate)
compounds. These monomers may be described as unsaturated
polycarbonates of polyols, e.g., glycols. The first monomer
component may be prepared by procedures well known in the art,
e.g., as described in U.S. Pat. Nos. 2,370,567 and 2,403,113.
In reference to general formula I, R.sub.1 is a radical derived
from an allyl group which may be substituted at the 2-position with
a halogen, most notably chlorine or bromine, or an alkyl group
containing from 1 to 4, e.g., 1 to 2, carbon atoms. Generally, the
alkyl substituent is methyl or ethyl. The R.sub.1 radical may be
represented by the following general formula IV:
wherein R.sub.2 is hydrogen, halogen or a C.sub.1 to C.sub.4 alkyl
group. Most commonly, R.sub.2 is hydrogen and consequently R.sub.1
is the unsubstituted allyl group, H.sub.2 C.dbd.CH--CH.sub.2
--.
In reference to general formula I, R is a polyvalent radical
derived from a polyol which can be an aliphatic, cycloaliphatic or
an aromatic polyol containing 2, 3, 4, 5 or 6 hydroxy groups.
Typically, the polyol contains 2 hydroxy groups, i.e., a glycol or
bisphenol. The aliphatic polyol may be linear or branched and
contain from 2 to 10 carbon atoms. Commonly, the aliphatic polyol
is an alkylene glycol having from 2 to 4 carbons atoms, ethylene
glycol, propylene glycol, trimethylene glycol, tetramethylene
glycol, or a poly(C.sub.2 -C.sub.4) alkylene glycol, e.g.,
diethylene glycol, triethylene glycol, etc. Other useful polyols
include aromatic polyols, such as bisphenols, e.g.,
4,4'-isopropylidenediphenol, and cycloaliphatic polyols, such as
biscyclohexanols, e.g., 4,4'-isopropylidenebiscyclohexanol.
Specific examples of polyol(allyl carbonate) monomers that may be
used as the first monomer component include: ethylene glycol
bis(2-chloroallyl carbonate), ethylene glycol bis(allyl carbonate),
diethylene glycol bis(2-methylallyl carbonate), diethylene glycol
bis(allyl carbonate), triethylene glycol bis(allyl carbonate),
propylene glycol bis(2-ethylallyl carbonate), 1,3-propanediol
bis(allyl carbonate), 1,3-butanediol bis(allyl carbonate), 1,4
butanediol bis(2-bromoallyl carbonate), dipropylene glycol
bis(allyl carbonate), trimethylene glycol bis(2-ethylallyl
carbonate), pentamethylene glycol bis(allyl carbonate),
4,4'-isopropylidenediphenol bis(allyl carbonate), and
4,4'-isopropylidenebiscyclohexanol bis(allyl carbonate). The
preferred polyol(allyl carbonate) monomer is diethylene glycol
bis(allyl carbonate).
A detailed description of polyol(allyl carbonate) monomers that may
be used to prepare the first monomer component of the composition
of the present invention is found in U.S. Pat. No. 4,637,698 at
column 3, line 33 through column 5, line 61. That disclosure is
hereby incorporated by reference and is summarized above. As used
in the present description with reference to the first monomer
component, the term polyol(allyl carbonate) monomer or like names,
e.g., diethylene glycol bis(allyl carbonate), is intended to mean
and include the named monomers or prepolymers thereof and any
related monomer or oligomer species contained therein.
The polymerizable organic composition of the present invention
contains also a second monomer component as defined with reference
to general formula II. Typically, the second monomer component is
present in an amount of from 2% to 35%, preferably from 2% to 25%
and more preferably from 2% to 15% by weight, based on the total
weight of monomer components.
A particularly preferred second monomer component can be defined
with reference to general formula II, wherein the sum of m and n is
from 15 to 40, e.g., .25 to 35, R.sub.3 and R.sub.4 are each
methyl, R.sub.5 and R.sub.6 are each hydrogen, and A is a divalent
linking group according to general formula III wherein ##STR7##
represents a divalent benzene group, p and q are each 0, and X is
--C(CH.sub.3).sub.2 --.
The second monomer component may be prepared by methods which are
well known in the art. One such commonly used method involves a
two-step process. In the first step, a polyol, e.g.,
4,4'-isopropylidenediphenol, is reacted with an oxirane containing
substance, for example ethylene oxide, propylene oxide,
.alpha.-butylene oxide or .beta.-butylene oxide, to form what is
commonly referred to as an ethoxylated, propoxylated or butoxylated
polyol having hydroxy functionality. In the second step, the
ethoxylated, propoxylated or butoxylated polyol is esterified, or
transesterified, with an alpha-beta unsaturated acid or ester such
as methacrylic acid, an alkyl methacrylate, an acrylic acid, an
alkyl acrylate, or a combination thereof. The second step-results
in the formation of the second monomer component.
Examples of polyols suitable for use in the first step of preparing
the second monomer component include: straight chain alkylene
glycols such as ethylene glycol, propylene glycol, trimethylene
glycol, tetramethylene glycol, or diethylene glycol, triethylene
glycol; branched chain alkylene glycols such as 1,2-propanediol,
2-methyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol,
2,3-butanediol; phenylene diols such as ortho, meta and para
dihydroxy benzene; alkyl substituted phenylene diols such as
2,6-dihydroxytoluene, 3-methylcatechol, 4-methylcatechol,
2-hydroxybenzyl alcohol, 3-hydroxybenzyl alcohol, and
4-hydroxybenzyl alcohol; dihydroxybiphenyls such as
4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl; bisphenols such
as 4,4'-isopropylidenediphenol; 4,4'-oxybisphenol;
4,4'-dihydroxybenzenephenone; 4,4'-thiobisphenol; phenolphthlalein;
bis(4-hydroxyphenyl)methane; 4,4'-(1,2-ethenediyl)bisphenol; and
4,4'-sulfonylbisphenol; halogenated bisphenols such as
4,4'-isopropylidenebis(2,6-dibromophenol),
4,4'-isopropylidenebis(2,6-dichlorophenol) and
4,4'-isopropylidenebis(2,3,5,6-tetrachlorophenol); and
biscyclohexanols, which can be prepared by hydrogenating the
corresponding bisphenols, such as
4,4'-isopropylidenebiscyclohexanol; 4,4'-oxybiscyclohexanol;
4,4'-thiobiscyclohexanol; and bis(4-hydroxycyclohexanol)methane
In a particularly preferred embodiment of the present invention,
the polymerizable organic composition comprises di(ethylene glycol)
bis(allyl carbonate) as the first monomer component and from 2% to
15% by weight, based on the total weight of monomer components, of
a second monomer component, which is defined in reference to
general formula II, wherein the sum of m and n is from 25 to 35,
e.g., 30, R.sub.3 and R.sub.4 are each methyl, R.sub.5 and R.sub.6
are each hydrogen, and A is a divalent linking group according to
general formula III wherein ##STR8## represents a divalent benzene
group, p and q are each 0, and X is --C(CH.sub.3).sub.2 --.
Optionally, from 0.5% to 30% by weight, based on the total weight
of monomer components, of a third monomer component may also be
present in the polymerizable organic composition of the present
invention. The third monomer component is different than the first
and second monomer components, has ethylenic unsaturation, and is
polymerizable by free radical initiation.
The third monomer component may be added to the polymerizable
composition for example, to enhance the hardness of polymerizates
prepared from the polymerizable organic compositions of the present
invention. As used herein, "ethylenic unsaturation" is meant to
include allylic unsaturation, alpha-beta ethylenic unsaturation,
and vinyl unsaturation. The third monomer component may preferably
represent from 0.5% to 20% and more preferably from 0.5% to 10% by
weight of the polymerizable composition, based on total weight of
monomer components. The third monomer component may have more than
one ethylenic unsaturated group which is polymerizable by free
radical initiation.
Examples of suitable monomers which may be used as the third
monomer component include: acrylic acid, methacrylic acid, esters
of acrylic acid such as methyl acrylate and 2-hydroxyethyl
acrylate, esters of methacrylic acid, such as methyl methacrylate,
2-hydroxyethyl methacrylate and phenoxyethyl methacrylate, and
vinyl esters such as vinyl acetate. Examples of suitable monomers,
having more than one free radical polymerizable group, which may be
used as the third monomer component include: allyl methacrylate,
ethyleneglycol dimethacrylate, triallyl cyanurate, pentaerythritol
tetraacrylate, di-pentaerythritoltriacrylate,
di-pentaerythritolpentaacrylate, ethoxylated trimethylolpropane
triacrylate having 0 to 20 ethoxy units, ethoxylated
trimethylolpropane trimethacrylate having 0 to 20 ethoxy units and
ethylenically-terminated aliphatic polyurethane monomers. By
"aliphatic polyurethane monomers" is meant polyurethane monomers
which are substantially free of carbamic nitrogen groups attached
directly to aromatic groups. A particularly preferred third monomer
component is vinyl acetate.
Aliphatic polyurethane monomers contemplated for use as the third
monomer component include those having terminal unsaturated groups
selected from acrylyl, methacrylyl and allyl groups, and mixtures
of such unsaturated groups. More particularly,
ethylenically-terminated aliphatic polyurethane monomers
contemplated include bis(allyl-terminated) aliphatic polyurethane
monomers, mono(allyl-terminated)--mono(acrylyl-terminated)
aliphatic polyurethane monomers, bis(acrylyl-terminated) aliphatic
polyurethane monomers, and mixtures of such aliphatic polyurethane
monomers. Bis(ethylenically-terminated) aliphatic polyesterurethane
monomers and bis(ethylenically-terminated) aliphatic
polyetherurethane monomers are also contemplated.
The aforedescribed aliphatic polyurethane monomers may be
represented by the general formulae, V-1, V-2 and V-3:
wherein D represents the terminal functional group containing allyl
unsaturation, D' represents the terminal functional group
containing acrylyl unsaturation, Y represents the residue of a
saturated aliphatic polyol, and B represents an aliphatic bis
carbamic moiety that originated from the corresponding aliphatic
diisocyanate. Group B in the foregoing graphic expressions may be
represented herein by the formula, --OC(O)--NH(E)NH--C(O)O--,
wherein E is the aliphatic (including cycloaliphatic) residue of
the aliphatic diisocyanate.
The group Y may be a diol, such as a C.sub.2 -C.sub.6 alkane diol,
diethylene glycol, a polyether diol, a polycarbonate diol or a
polyester diol, i.e., the residue remaining after removal of the
hydroxyl groups from the polyol, e.g., diol. For example, when the
polyol is butane diol, Y in the foregoing graphic expressions may
be represented by the formula, --CH.sub.2 --CH.sub.2 --CH.sub.2
--CH.sub.2 -- (or --(CH.sub.2).sub.4 --). Preferably, Y is the
residue of a polyester diol, diethylene glycol, or C.sub.2
-C.sub.6, e.g., C.sub.2 -C.sub.4, alkane diol, e.g., butane diol,
and is liquid at room temperature.
The terminal group D in the foregoing expressions contains allyl
unsaturation, and is preferably the allyl group, i.e., CH.sub.2
.dbd.CH--CH.sub.2 --, which originates, for example, from allyl
alcohol. The terminal group D' in the foregoing expressions, which
contains acrylyl unsaturation, may be acrylyl or methacrylyl
unsaturation, i.e., CH.sub.2 .dbd.CH(L)--C(O)--, wherein L is
hydrogen or methyl. The terminal group D' may also be represented
by the expression CH.sub.2 .dbd.C(L)--C(O)--O--M--, wherein M is an
alkylene group of from 2 to 6 carbon atoms, such as ethylene, and L
is hydrogen or methyl, e.g., the group derived from 2-hydroxyethyl
acrylate or methacrylate. The term "acrylyl", as used herein is
intended to include "methacrylyl", i.e., when "L" is methyl.
Diisocyanates that may be used to prepare the aliphatic urethane
component of the polymerizable composition include aliphatic
diisocyanates, cycloaliphatic diisocyanates and tetramethyl xylene
diisocyanate [CAS 2778-41-8]. For convenience and brevity, such
isocyanates will be referred to collectively as aliphatic
diisocyanates. Such materials are substantially free of isocyanato
groups attached directly to aromatic groups. By substantially free
of isocyanato groups attached directly to aromatic groups is meant
that the aliphatic diisocyanate contains 1 percent or less of
diisocyanato groups attached directly to aromatic groups. Thus the
aliphatic urethane contains a correspondingly small, if any at all,
amount of urethane groups the carbamic nitrogen atoms of which are
attached directly to aromatic groups. Examples of suitable
diisocyanates include those listed in U.S. Pat. No. 5,221,721 at
column 5, lines 34 through 49, which disclosure is incorporated
herein by reference.
Polyester diols may be prepared by techniques well known in the
art, e.g., using saturated dicarboxylic acids or anhydrides thereof
(or combinations of acids and anhydrides) and polyhydric alcohols,
or by ring opening of caprolactones, e.g., epsilon caprolactone,
with a straight chain glycol, e.g., diethylene glycol. Such
polyester diols and their manner of preparation are well known and
are fully described in the published literature. Many are
commercially available in various molecular weights. Polyhydric
alcohols which may be used in the preparation of the polyester
diols include those listed and described in U.S. Pat. No. 5,221,721
at column 6, lines 8 through 22, which disclosure is incorporated
herein by reference. Examples of polyester diols contemplated for
use in preparing aliphatic polyurethane monomers, include those
listed and described in U.S. Pat. No. 5,221,721 at column 6, lines
32 through 41, which disclosure is incorporated herein by
reference.
Polycarbonate diols that may be used to prepare aliphatic
polyurethane monomers are described in column 6, lines 42 through
68 and column 7, lines 1 through 19 of U.S. Pat. No. 5,221,721.
Polyether diols, e.g., poly(oxyethylene)glycols,
poly(oxy-1,2-propylene)glycols, and poly(oxy-1,2-butylene)glycol,
that may be used to prepare aliphatic polyurethane monomers are
described in U.S. Pat. No. 5,221,721 at column 7, lines 20 through
47. Alkane diols contemplated for use in preparing aliphatic
polyurethane monomers are described in U.S. Pat. No. 5,221,721 at
column 7, lines 48 through 54. All of the aforedescribed
disclosures are incorporated herein by reference.
Polymerization of the polymerizable organic composition of the
present invention may be accomplished by adding to the composition
an initiating amount of material capable of generating free
radicals, such as organic peroxy compounds, i.e., an initiator.
Methods for polymerizing polyol(allyl carbonate) compositions are
well known to the skilled artisan and any of those well known
techniques may be used to polymerize the aforedescribed
polymerizable organic compositions. Suitable examples of organic
peroxy compounds, that may be used as initiators include:
peroxymonocarbonate esters, such as tertiarybutylperoxy isopropyl
carbonate; peroxydicarbonate esters, such as di(2-ethylhexyl)
peroxydicarbonate, cyclohexylperoxydicarbonate, di(secondary butyl)
peroxydicarbonate and diisopropylperoxydicarbonate; diacyperoxides,
such as 2,4-dichlorobenzoyl peroxide, isobutyryl peroxide, decanoyl
peroxide, lauroyl peroxide, propionyl peroxide, acetyl peroxide,
benzoyl peroxide, p-chlorobenzoyl peroxide; peroxyesters such as
t-butylperoxy pivalate, t-butylperoxy octylate, and
t-butylperoxyisobutyrate; methylethylketone peroxide,
acetylcyclohexane sulfonyl peroxide, and azobisisobutyronitrile.
Preferred initiators are those that do not discolor the resulting
polymerizate. A preferred initiator is diisopropyl
peroxydicarbonate.
The amount of initiator used to initiate and polymerize the
polymerizable organic compositions of the present invention vary
and will depend on the particular initiator used. Only that amount
that is required to initiate and sustain the polymerization
reaction is required, i.e., an initiating amount. With respect to
the preferred peroxy compound, diisopropyl peroxydicarbonate,
typically between 2.0 and 5.0 parts of that initiator per 100 parts
of the polymerizable organic composition (phm) may be used. More
usually, between 2.5 and 4.0 phm is used to initiate the
polymerization. The amount of initiator and the consequent cure
cycle should be adequate to produce a polymerizate having a 15
second Barcol hardness of at least 1, preferably, at least 4, e.g.,
from 4 to 35. Typically, the cure cycle involves heating the
polymerizable organic composition in the presence of the initiator
from room temperature to 85.degree. C. to 125.degree. C. over a
period of from 4 hours to 30 hours.
Various conventional additives may be incorporated into the
polymerizable organic composition of the present invention. Such
additives may include light stabilizers, heat stabilizers, and
ultraviolet light absorbers. In addition, it is contemplated that a
form of organic photochromic substance resistant to the effects of
the initiator may also be added to the polymerizable organic
composition of the present invention. Such organic photochromic
substances include photochromic pigments and photochromic compounds
encapsulated in metal oxides, the latter of which are described in
U.S. Pat. Nos. 4,166,043 and 4,367,170.
It is also contemplated that a polymerization moderator may be
added to the polymerizable organic composition of the present
invention to minimize the formation of distortions, such as
striations, in polymerizates obtained therefrom. Suitable
polymerization moderators include for example, dilauryl
thiodipropionate, terpinolene,
1-isopropyl-4-methyl-1,4-cyclohexadiene, alpha-methyl styrene,
4-tert-butylpyrocatechol, and mixtures thereof. The polymerization
moderator may be added to the polymerizable organic composition of
the present invention in an amount from 0.01% to 20% by weight,
based on the total weight of polymerizable organic composition.
It is further contemplated that a flexibilizing additive having no
radically polymerizable groups, henceforth referred to as a
nonpolymerizable flexibilizing additive, may be added to
polymerizable organic compositions of the present invention. Such a
nonpolymerizable flexibilizing additive is different than the
aforedescribed first, second and third monomer components. The
nonpolymerizable flexibilizing additive, or mixtures of
nonpolymerizable flexibilizing additives, may be added in an amount
of from 0.05% to 15%, preferably from 0.5% to 10% and more
preferably from 2% to 6% by weight, based on the total weight of
the monomer components and the weight of the nonpolymerizable
flexibilizing additive(s). The nonpolymerizable flexibilizing
additive may be used in combination with, the first and second
monomer components or the first, second and third monomer
components. The nonpolymerizable flexibilizing additive may be
nonaromatic or aromatic.
Examples of suitable nonpolymerizable flexibilizing additives
include, alkoxylated phenol benzoate, alkoxylated naphthol
benzoate, 1,3-bis(phenylthio)propane, bis(phenylthio) alkylene
ether, the reaction product of phenyl chloroformate and
dimercaptan, the reaction product of dimercaptan and phosgene
endcapped with phenol, cinnamates, triphenyl phosphite,
tri(2-ethylhexyl) trimellitate, triisodecyl trimellitate,
poly(alkylene glycol) dinaphthoate, 2-ethylhexyl diphenylphosphate,
isodecyl diphenyl phosphate, tricresyl phosphate, poly(alkylene
glycol) dibenzoates, e.g., poly(ethylene glycol) dibenzoate and
poly(propylene glycol) dibenzoate, esters of phthalic acid,
isophthalic acid, and terephthalic acid, e.g., dioctyl phthalate,
and a member represented by the following general formula VI:
##STR9## wherein e and f are each a positive number, the sum of e
and f being from 0 to 70, R.sub.5 and R.sub.6 are each hydrogen or
C.sub.1 to C.sub.2 alkyl, preferably hydrogen or methyl and A is a
divalent linking group selected from the group consisting of
straight or branched chain alkylene (usually containing from 1 to 8
carbon atoms), phenylene, C.sub.1 -C.sub.9 alkyl substituted
phenylene and a group represented by general formula III, ##STR10##
wherein, R.sub.7 and R.sub.8 are each C.sub.1 -C.sub.4 alkyl,
chlorine or bromine, p and q are each an integer from 0 to 4,
##STR11## represents a divalent benzene group or a divalent
cyclohexane group and X is O, S, --S(O.sub.2)--, --C(O)--,
--CH.sub.2 --, --C(CH.sub.3).sub.2 --, --C(CH.sub.3)(C.sub.6
H.sub.5)-- or ##STR12## when ##STR13## is the divalent benzene
group, and X is O, S, --CH.sub.2 --, or --C(CH.sub.3).sub.2 -- when
##STR14## is the divalent cyclohexane group.
Nonpolymerizable flexibilizing additives, described with reference
to general formula VI where the sum of e and f is greater than 0,
may be prepared by methods which are well known in the art. One
such commonly used method involves reacting a polyol, e.g.,
4,4'-isopropylidenediphenol with an oxirane containing substance,
e.g., ethylene oxide, propylene oxide, .alpha.-butylene oxide or
.beta.-buoylene oxide, to form the nonpolymerizable flexibilizing
additive represented by general formula VI.
Examples of suitable polyols, for preparing nonpolymerizable
flexibilizing additives represented by general formula VI wherein
the sum of e and f is greater than 0, or for use as the
nonpolymerizable flexibilizing additive wherein the sum of e and f
is 0, include those described with respect to the first step of
preparing the second monomer component, exclusive of
4,4'-(1,2-ethenediyl)bisphenol.
A preferred nonpolymerizable flexibilizing additive may be defined
with reference to general formula VI wherein the sum of e and f is
from 25 to 35, R.sub.5 and R.sub.6 are each hydrogen, and A is a
divalent linking group according to general formula III, wherein
##STR15## represents a divalent benzene group, p and q are each 0
and X is --C(CH.sub.3).sub.2 --.
Polymerizates obtained from polymerization of polymerizable organic
compositions of the present invention are solid and preferably
transparent or optically clear so that they may be used for optical
lenses, such as plano and ophthalmic lenses, sun lenses, windows,
automotive transparencies, e.g., windshields, T-roofs, sidelights
and backlights, and for aircraft transparencies, etc. When used to
prepare photochromic articles, e.g., lenses, the polymerizate
should be transparent to that portion of the electromagnetic
spectrum which activates the photochromic substance(s) incorporated
in the matrix, i.e., that wavelength of ultraviolet (UV) light that
produces the colored or open form of the photochromic substance and
that portion of the visible spectrum that includes the absorption
maximum wavelength of the photochromic substance in its UV
activated form, i.e., the open form.
Photochromic compounds that may be utilized with the polymerizates
of the present invention are organic photochromic compounds or
substances containing same that may be incorporated, e.g.,
dissolved, dispersed or diffused into such polymerizates.
A first group of organic photochromic substances contemplated for
use to form the photochromic articles of the present invention are
those having an activated absorption maximum within the visible
range of greater than 590 nanometers, e.g., between greater than
590 to 700 nanometers. These materials typically exhibit a blue,
blueish-green, or blueish-purple color when exposed to ultraviolet
light in an appropriate solvent or matrix. Many of such compounds
are described in the open literature. For example,
spiro(indoline)naphthoxazines have been described, among others, in
U.S. Pat. Nos. 3,562,172; 3,578,602; 4,215,010; and 4,342,668.
Spiro(indoline)naphthoxazines having certain substituents at the 8'
and 9' positions of the naphthoxazine portion of the molecule are
described in U.S. Pat. No. 5,405,958.
Spiro(indoline)pyridobenzoxazines are described in U.S. Pat. No.
4,637,698. Spiro(benzindoline)pyridobenzoxazines and
spiro(benzindoline)naphthoxazines are described in U.S. Pat. No.
4,931,219. Spiro(benzindoline)naphthopyrans are described in
Japanese Patent Publication 62/195383. Spiro(indoline)benzoxazines
are described in U.S. Pat. No. 4,816,584.
Spiro(indoline)benzopyrans, spiro(indoline)naphthopyrans and
spiro(indoline)quinopyrans are described, for example, in U.S.
4,880,667. Benzopyrans and naphthopyrans having a
nitrogen-containing substituent at the 2-position of the pyran ring
are described in U.S. Pat. No. 4,818,096. Spiro(indoline)pyrans are
also described in the text, Techniques in Chemistry, Volume III,
"Photochromism," Chapter 3, Glenn H. Brown, Editor, John Wiley and
Sons, Inc., New York, 1971.
A second group of organic photochromic substances contemplated for
use to form the photochromic articles of the present invention are
those having at least one absorption maximum and preferably two
absorption maxima, within the visible range of between 400 and less
than 500 nanometers. These materials typically exhibit a
yellow-orange color when exposed to ultraviolet light in an
appropriate solvent or matrix. Such compounds include certain
chromenes, i.e., benzopyrans and naphthopyrans. Many of such
chromenes are described in the open literature, e.g., U.S. Pat.
Nos. 3,567,605; 4,826,977; 5,066,818; 4,826,977; 5,066,818;
5,466,398; 5,384,077; 5,238,931; and 5,274,132.
A third group of organic photochromic substances contemplated for
use to form the photochromic articles of the present invention are
those having an absorption maximum within the visible range of
between 400 to 500 nanometers and another absorption maximum within
the visible range of between 500 to 700 nanometers. These materials
typically exhibit color(s) ranging from yellow/brown to purple/gray
when exposed to ultraviolet light in an appropriate solvent or
matrix. Examples of these substances include certain benzopyran
compounds, having substituents at the 2-position of the pyran ring
and a substituted or unsubstituted heterocyclic ring, such as a
benzothieno or benzofurano ring fused to the benzene portion of the
benzopyran. Such materials are the subject of U.S. Pat. No.
5,429,774.
Other photochromic substances contemplated are photochromic
organo-metal dithzonates, i.e., (arylazo)thioformic
arylhydrazidates, e.g., mercury dithizonates which are described
in, for example, U.S. Pat. No. 3,361,706. Fulgides and fulgimides,
e.g. the 3-furyl and 3-thienyl fulgides and fulgimides which are
described in U.S. Pat. No. 4,931,220 at column 20, line 5 through
column 21, line 38.
The disclosures relating to such photochromic compounds in the
aforedescribed patents are incorporated herein, in toto, by
reference. The photochromic articles of the present invention may
contain one photochromic compound or a mixture of photochromic
compounds, as desired. Mixtures of photochromic compounds may be
used to attain certain activated colors such as a near neutral gray
or brown.
Each of the photochromic substances described herein may be used in
amounts and in a ratio (when mixtures are used) such that a
polymerizate to which the mixture of compounds is applied or in
which they are incorporated exhibits a desired resultant color,
e.g., a substantially neutral color such as shades of gray or brown
when activated with unfiltered sunlight, i.e., as near a neutral
color as possible given the colors of the activated photochromic
compounds. The relative amounts of the aforesaid photochromic
compounds used will vary and depend in part upon the relative
intensities of the color of the activated species of such
compounds, and the ultimate color desired.
The photochromic compounds or substances described herein may be
applied to or incorporated into the polymerizate by various methods
described in the art. Such methods include dissolving or dispersing
the substance within the polymerizate, e.g., imbibition of the
photochromic substance into the polymerizate by immersion of the
polymerizate in a hot solution of the photochromic substance or by
thermal transfer; providing the photochromic substance as a
separate layer between adjacent layers of the polymerizate, e.g.,
as a part of a polymer film; and applying the photochromic
substance as part of a coating placed on the surface of the
polymerizate. The term "imbibition" or "imbibe" is intended to mean
and include permeation of the photochromic substance alone into the
polymerizate, solvent assisted transfer absorption of the
photochromic substance into a porous polymer, vapor phase transfer,
and other such transfer mechanisms.
The amount of photochromic substance or composition containing same
applied to or incorporated into the polymerizate is not critical
provided that a sufficient amount is used to produce a photochromic
effect discernible to the naked eye upon activation. Generally such
amount can be described as a photochromic amount. The particular
amount used depends often upon the intensity of color desired upon
irradiation thereof and upon the method used to incorporate or
apply the photochromic substances. Typically, the more photochromic
substance applied or incorporated, the greater is the color
intensity. Generally, the amount of total photochromic substance
incorporated into or applied to a photochromic optical polymerizate
may range from 0.15 to 0.35 milligrams per square centimeter of
surface to which the photochromic substance(s) is incorporated or
applied.
The present invention is more particularly described in the
following examples, which are intended to be illustrative only,
since numerous modifications and variations therein will be
apparent to those skilled in the art. Unless otherwise specified,
all parts and all percentages are by weight.
EXAMPLES 1-2
Table 1 describes two polymerizable monomer compositions. Example 1
is representative of an embodiment of the present invention.
Example 2 is a comparative example. The level of diisopropyl
peroxydicarbonate used in each of Examples 1 and 2 is selected so
that the polymerizates obtained therefrom are substantially
completely cured.
TABLE 1 ______________________________________ Example Basic
Ingredients, Parts 1 2 ______________________________________ CR-39
.RTM. monomer.sup.a 94 100 SR-9036 monomer.sup.b 6 0 Diisopropyl
peroxydicarbonate 3.7 3.0 ______________________________________
.sup.a CR39 .RTM. monomer is a diethylene glycol bis(allyl
carbonate) monomer obtained from PPG Industries Inc. .sup.b SR9036
monomer, obtained from Sartomer Inc., is a bismethacrylate of
ethoxylated 4,4isopropylidenediphenol having an average of 30 moles
of ethylene oxide.
Cast sheets of the polymerizable monomer compositions of Table 1
were made in the following manner. Each monomer composition was
transferred to a suitable vessel and the designated amount of
di-isopropyl peroxydicarbonate was added. The resulting initiated
polymerizable monomer composition was mixed using a magnetic stir
plate and magnetic stir bar at a temperature of 4.degree. C. The
initiated monomer composition was then filtered through a 0.45
micron MAGNA nylon filter using a 316 stainless steel 1.5 liter
pressure filter holder, under 20 pounds per square inch (138 kPa)
of nitrogen gas. The resulting filtered composition was then poured
into glass molds having the following interior dimensions,
15.24.times.15.24.times.0.32 cm. The filled molds were then placed
in a heated water bath and cured using the appropriate cure cycle
described in Table 2. The cure cycle used was optimized for each of
Examples 1 and 2 so that polymerizates obtained therefrom would be
substantially completely cured. Physical properties of the sheets
were measured and the results are tabulated in Table 3.
TABLE 2* ______________________________________ Cure Cycles
Cummulative Hours Oven Temperature .degree. C.
______________________________________ Cure Cycle For Example 1 0
39 2.3 41 8 44 12.5 47 16.5 51 20 56 22 68 24 88 26 90 (end of
cycle) Cure Cycle For Example 2 0 39 8.3 55 10.1 58 11.4 63 13 66
14.5 70 15.2 77 16.5 90 18.5 91 (end of cycle)
______________________________________ *The rate of temperature
change represented in Table 2 was, in all instances, linear.
TABLE 3 ______________________________________ Physical Data
Example 1 2 ______________________________________ Physical Test %
Transmitance.sup.c 93.7 94.0 Yellowness Index.sup.d 1.09 0.57 L*
97.51 97.62 a* -0.40 -0.10 b* 0.73 0.34 Refractive Index.sup.e
1.4975 1.4965 (n.sub.d.sup.20) Abbe Number 55 57 Density at
25.degree. C. (g/cc) 1.299 1.316 Physical Test Barcol Hardness (0
Seconds).sup.f 9 29 Barcol Hardness (15 seconds).sup.f 1 23 Heat
Distortion Temperature.sup.g 42 to 44 51 to 58 (.degree. C. at 10
mils) Total Deflection at 130.degree. C..sup.h 50 to 56 36 to 37
(mils) Bayer Abrasion Resistance.sup.i 0.9 1.0 Youngs Modulus
(GPa).sup.j 1.68 3.00 ______________________________________ .sup.c
Percent transmittance was determined in accordance with ASTM D
1003, using a Hunter Lab model D25P9 colorimeter employing a Lumen
C ligh source. .sup.d Yellowness Index, L*, a* and b* were
determined in accordance with ASTM D 192570, using a Hunter Lab
model D25P9 colorimeter employing a Lumen C light source. .sup.e
Refractive Index n.sub.d.sup.20 was determined in accordance with
ASTM D54250, using a Bausch & Lomb Abbe3L refractometer. .sup.f
Barcol Hardness was determined in accordance with ASTM D 258381,
taking scale readings immediately after the Barcol impresser point
penetrated the specimen, and 15 seconds thereafter. .sup.g The Heat
Distortion Temperature was measured, at a deflection of 254 microns
(10 mils), in accordance with ASTM D 64886 using a Custom
Scientific Instruments Model HDV3 DTUL/Vicat Softening Point
Apparatus. .sup.h Total Deflection at 130.degree. C. was determined
in accordance with ASTM D 64886 using a Custom Scientific
Instruments Model HDV3 DTUL/Vicat Softening Point Apparatus. .sup.i
Bayer Abrasion Resistance was determined in accordance with ASTM
F73581, using an oscillating sand abrasion device. The Bayer
Abrasion Resistance results are shown as ratios relative to
homopolymers of CR39 .RTM. monomer as the standard, (result for the
sample in question/result for standard). A Bayer Abrasion
Resistance value greater than 1.0 indicates that the sample in
question has better abrasion resistance relative to a sample
prepared from the standard. .sup.j Young's Modulus was determined,
using a Fischer Scope H100 instrument, in accordance with the
instrument manufacturer's instructions Smaller Young's Modulus
values indicate increased flexibility.
The data of Table 3 shows that polymerizates obtained from
polymerizable monomer compositions of the present invention have
greater flexibility and essentially equivalent abrasion resistance
relative to polymerizates obtained from a homopolymer of
CR-39.sup..circle-w/dot. monomer.
EXAMPLES 3-4
Plano lenses, 12 mm thick, were cast from initiated polymerizable
monomer compositions having the same compositions as described in
Table 1 using glass plano lens molds having interior dimensions of
75 mm diameter.times.12 mm, the preparative method described in the
previous Example, and the cure cycles described in Table 2. The
cast plano lenses were imbibed with a combination of
3,3-di(4-methoxyphenyl)-13-hydroxy-13-(1-methylethyl)--indeno[2,1-f]naphth
o[1,2-b]pyran, and 2,2-diphenyl-5-(ethoxycarbonylmethoxy
carbonyl)-8-methyl-[2H]-naphtho-[1,2-b] pyran as follows: Resin
solutions of the photochromic substances were spin coated onto the
convex surfaces of the cast lenses. The coated cast lenses were
then allowed to dry under an infrared lamp for 20 minutes followed
by heating for 6 hours in a forced air oven set at 135.degree. C.
The imbibed lenses were then removed from the oven and allowed to
cool to room temperature. The imbibed lenses were then thoroughly
washed with 32.degree. C. water to remove the resin solution.
Photochromic performance data for the imbibed cast lenses were
determined through use of an optical bench. Prior to testing on the
optical bench, the imbibed cast lenses were exposed to 365
nanometer ultraviolet light for about 15 minutes to activate the
photochromic compounds and then placed in a 76.degree. C. oven for
about 15 minutes to bleach or inactivate the photochromic
compounds. The imbibed cast lenses were then cooled to room
temperature, exposed to fluorescent room lighting for at least 2
hours and then kept covered for at least 2 hours prior to testing
on an optical bench maintained at 23.9.degree. C.
The optical bench was equipped with a 300 watt Xenon arc lamp
operated at about 200 watts, a remote controlled shutter, a Schott
WG-320 nm cut off filter, which removes short wavelength radiation,
neutral density filter(s) and a constant temperature water bath in
which the lens to be tested was immersed. A collimated beam of
light from a tungsten lamp was passed through the cast lens at a
small angle to the normal of the center of the convex side of the
plano lens. After passing through the lens, the light from the
tungsten lamp impinged a beam splitter which split the beam into
two secondary beams of equal intensity. The reflected secondary
beam was directed through a 480 nm band pass filter to a detector.
The unreflected secondary beam was directed through a 620 nm band
pass photopic filter to a detector. The photopic filter passes
wavelengths such that the detector mimics the response of the human
eye. The output signals from the detector(s) were processed by a
radiometer which delivered data to a computer. The following Table
4 lists photochromic performance data obtained from the tested
plano lenses.
TABLE 4 ______________________________________ Photochromic
Performance Example Polymerizable Monomer 3 4 Compositions
according to Example 1 2 ______________________________________
Test Net Absorbance.sup.k 1.84 ND.sup.1 at 390 nm .DELTA.OD.sup.l
0.279 ND 8 minutes, (29.4.degree. C.) B/O Ratio.sup.m 1.11 ND
Bleach Half Life (t.sub.1/2).sup.n 46 ND (seconds)
______________________________________ .sup.1 ND = Not Determined.
Lenses cast according to Example 4 could not be imbibed to any
appreciable extent, and as such photochromic performanc data
relative to Example 4 was not determined. .sup.k Net Absorbance at
390 nm, (viz., absorbance of the imbibed lens in the bleached state
minus the absorbance of the uncoated lens) was determined at room
temperature using a Varian Model Cary 3 spectrophotometer. .sup.l
Change in optical density (.DELTA.OD) was determined on the optica
bench by inserting an imbibed lens, in the bleached state, into the
sampl holder, adjusting the transmittance scale to 100%, opening
the shutter from the Xenon lamp to provide ultraviolet radiation to
change the test square from the bleached state to an activated
(i.e., substantially darkened) state, measuring the transmittance
in the # activated state, and calculating the change in optical
density according the formula .DELTA.OD = log(100/% Ta) where % Ta
is the percent transmittance in the activated state and the
logarithm is to the base 10. The period of exposure to the
ultraviolet light from the Xenon lamp at the time the percent
transmittance is determined, and the temperature of the water bath,
are both noted. .sup.m The B/O Ratio is a measure of the optical
density at 570 nm over the optical density at 470 nm. The
respective optical density values were determined using the optical
bench as described above. .sup.n The Bleach Half Life (T.sub.1/2)
is the time interval in seconds for the absorbance of the activated
form of the imbibed lens to reach one half the highest absorbance
at 29.4.degree. C. after removal of the sourc of activating
light.
The data of Table 4 shows that photochromic articles made from
polymerizates of the present invention may be successfully imbibed
with photochromic substances to produce articles that have good
photochromic performance properties compared to polymerizates
prepared from homopolymers of CR-39.sup..circle-w/dot. monomer.
The present invention has been described with reference to specific
details of particular embodiments thereof. It is not intended that
such details be regarded as limitations upon the scope of the
invention except insofar as and to the extent that they are
included in the accompanying claims.
* * * * *